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The human neutrophil lipocalin (HNL), a member of the large family of lipocalins that exhibit various physiological functions, is coexpressed in granulocytes with progelatinase B (MMP-9). Part of it is covalently bound to the proenzyme and therefore may play a possible role in the activation process of promatrix metalloproteinases. We now report that HNL is able to accelerate the direct activation of promatrix metalloproteinases slightly. A significant enhancement of the activity could be demonstrated for the HgCl 2 -and the plasma kallikrein-induced activation of all three secretory forms of proMMP-9 and of proMMP-8. The same activating effects were exerted by HNL isolated from granulocytes as well as by the recombinant forms expressed by the yeast Pichia pastoris or by Escherichia coli. This demonstrates that the carbohydrate moiety is not essential for the biological activity of HNL. Activation and activity enhancement are obviously mediated by entrapping the remaining N-terminal sequence residues of the partially truncated proenzyme into the hydrophobic binding pocket of the HNL. In conclusion these results document that HNL can exert an enzyme-activating effect in the regulation of inflammatory and pathophysiological responses of granulocytes in the physiological activation of MMPs that have been subject to limited proteolytic processing.

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Human neutrophil lipocalin (HNL) cDNA was amplified by PCR technology in combination with deoxyinosine containing oligonucleotides for cloning, sequencing and production of the recombinant protein in E. coll. The primers were targeted to the corresponding DNA backtranslate of the mature protein resulting in a PCR amplified 534 bp cDNA from different reverse transcripts of ovarian cancer cell line and bone marrow cell mRNAs. Sequence analysis revealed that two different cDNAs from ovarian cancer and bone marrow cells could be obtained. Cloning and expression of HNL cDNAs were performed in E. coil strain HMS 174 [DE3] using the pET system yielding in two recombinant proteins with a molecular weight of 21 kDa which is consistent with an 178 amino acid residues containing sequence of the mature HNL protein. N-terminal amino acid sequence analysis of the expression products showed an identical polypeptide sequence missing the E. coli processed starting methionine.

Background: It is unknown whether subscapularis management technique has an influence on the outcomes and complications of stemless total shoulder arthroplasty. The purpose of this study, therefore, was to compare outcomes and complications between subscapularis tenotomy, peel, and lesser tuberosity osteotomy used during stemless shoulder arthroplasty. Methods: We reviewed 188 stemless anatomic total shoulder arthroplasties and compared clinical and functional outcomes between those performed through a subscapularis tenotomy (n ¼ 68), subscapularis peel (n ¼ 65), or lesser tuberosity osteotomy (n ¼ 55). Patients were followed up clinically and radiographically at 6 months, 1 year, and 2 years postoperatively. Results: At 2 years postoperatively, no statistically significant differences in visual analog scale pain scores, American Shoulder and Elbow Surgeons scores, or patient-reported instability (P .19) were found between groups. Active external rotation was greater in the peel group (P ¼ .006) than in the tenotomy group but was not different compared with the lesser tuberosity osteotomy group (P ¼ .07). No statistically significant difference in clinical subscapularis failures was noted between groups (P ¼ .11); however, 2 patients in the peel group sustained a subscapularis failure requiring reoperation. Discussion: The results of this multicenter comparative analysis show that all 3 subscapularis management techniques are effective and safe in the short term when used with stemless anatomic total shoulder arthroplasty.